This page describes the JRuby IRB-based HBase Shell. It replaces the SQL-like HQL, the Shell found in HBase versions 0.1.x and previous. Some discussion of new shell requirements can be found in the Shell Replacement document.

To run the shell, do

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hadoop$redhat ${HBASE_HOME}/bin/hbase shell

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You'll be presented with a prompt like the following:

HBase Shell; enter 'help<RETURN>' for list of supported commands.
Version: 0.2.0-dev, r670701, Mon Jun 23 17:26:36 PDT 2008
hbase(main):001:0>

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Type 'help' followed by a return to get a listing of commands

hbase(main):001:0> help
HBASE SHELL COMMANDS:
 alter     Alter column family schema;  pass table name and a dictionary
           specifying new column family schema. Dictionaries are described
           below in the GENERAL NOTES section.  Dictionary must include name
           of column family to alter.  For example,

           To change or add the 'f1' column family in table 't1' from defaults
           to instead keep a maximum of 5 cell VERSIONS, do:
           hbase> alter 't1', {NAME => 'f1', VERSIONS => 5}

           To delete the 'f1' column family in table 't1', do:
           hbase> alter 't1', {NAME => 'f1', METHOD => 'delete'}

           You can also change table-scope attributes like MAX_FILESIZE
           MEMSTORE_FLUSHSIZE and READONLY.

           For example, to change the max size of a family to 128MB, do:
           hbase> alter 't1', {METHOD => 'table_att', MAX_FILESIZE => '134217728'}

 count     Count the number of rows in a table. This operation may take a LONG
           time (Run '$HADOOP_HOME/bin/hadoop jar hbase.jar rowcount' to run a
           counting mapreduce job). Current count is shown every 1000 rows by
           default. Count interval may be optionally specified. Examples:

           hbase> count 't1'
           hbase> count 't1', 100000

 create    Create table; pass table name, a dictionary of specifications per
           column family, and optionally a dictionary of table configuration.
           Dictionaries are described below in the GENERAL NOTES section.
           Examples:

           hbase> create 't1', {NAME => 'f1', VERSIONS => 5}
           hbase> create 't1', {NAME => 'f1'}, {NAME => 'f2'}, {NAME => 'f3'}
           hbase> # The above in shorthand would be the following:
           hbase> create 't1', 'f1', 'f2', 'f3'
           hbase> create 't1', {NAME => 'f1', VERSIONS => 1, TTL => 2592000, \
             BLOCKCACHE => true}

 describe  Describe the named table: e.g. "hbase> describe 't1'"

 delete    Put a delete cell value at specified table/row/column and optionally
           timestamp coordinates.  Deletes must match the deleted cell's
           coordinates exactly.  When scanning, a delete cell suppresses older
           versions. Takes arguments like the 'put' command described below

 deleteall Delete all cells in a given row; pass a table name, row, and optionally
           a column and timestamp

 disable   Disable the named table: e.g. "hbase> disable 't1'"

 drop      Drop the named table. Table must first be disabled. If table has
           more than one region, run a major compaction on .META.:

           hbase> major_compact ".META."

 enable    Enable the named table

 exists    Does the named table exist? e.g. "hbase> exists 't1'"

 exit      Type "hbase> exit" to leave the HBase Shell

 get       Get row or cell contents; pass table name, row, and optionally
           a dictionary of column(s), timestamp and versions.  Examples:

           hbase> g